Ballistic -resistant laminate assemblies and panels

ABSTRACT

A sheet of ballistic-resistant fiber strands includes a bi-directional array of bonding fibers interwoven with the ballistic-resistant fibers to form a fiber panel. In one embodiment, a sheet of laminated ballistic-resistant fibers is joined to the first sheet of laminated ballistic-resistant fibers with the ballistic-resistant fibers running in a second direction as compared to the first fibers. In yet another embodiment, individual laminated sheets of ballistic-resistant fibers are stitched together to form packets of sheets that may be used singularly or bundled together.

This application is a continuation-in-part application of U.S. patentapplication Ser. No. 10/421,627, entitled METHOD FOR FORMING OR SECURINGUNIDIRECTIONALLY-ORIENTED FIBER STRANDS IN SHEET FORM, SUCH AS FOR USEIN A BALLISTIC-RESISTANT PANEL, which is a continuation of U.S. patentapplication Ser. No. 09/528,782, entitled METHOD FOR FORMING OR SECURINGUNIDIRECTIONALLY ORIENTED FIBER STRANDS IN SHEET FORM, SUCH AS FOR USEIN A BALLISTIC-RESISTANT PANEL, filed Mar. 17, 2002, which isincorporated herein in its entirety by reference, and which claimspriority to U.S. Provisional Patent Application No. 60/125,403, alsoincorporated herein in its entirety by reference.

TECHNICAL FIELD

This invention relates to forming or securing fiber strands in sheetform and, more particularly, to forming or securing fiber strands insheet form for use in a ballistic-resistant laminate.

BACKGROUND OF THE INVENTION

Unidirectional fiber materials are used in ballistic-resistantstructures and are disclosed, e.g., in U.S. Pat. Nos. 4,916,000,4,079,161, 4,309,487, and 4,213,812. A non-woven ballistic-resistantlaminate referred to by the trademark “Spectra-Shield” is manufacturedby Allied-Signal, Inc. The laminate structure is used in soft body armorto protect the wearer against high-velocity bullets and fragments.“Spectra-shield” was made by first forming a non-woven unidirectionaltape, which was composed of unidirectional polyethylene fibers and anelastic resin material that held the fibers together. The resinpenetrated the fibers, effectively impregnating the entire structurewith the resin product. Two layers, or arrays, of the unidirectionaltape were then laminated together (cross-plied) at right angles to forma panel. The panel was then covered on both sides with a film ofpolyethylene. The film prevented adjacent panels from sticking togetherwhen the panels were layered in the soft body armor. The final panel washeavier and stiffer than desired for use as a ballistic-resistant panel.The weight and stiffness were due in part to the penetration of theentire structure with the resin product.

Non-woven ballistic-resistant laminates without resins are disclosed,e.g., in U.S. Pat. Nos. 5,437,905, 5,443,882, 5,443,883, and 5,547,536.A sheet of non-woven ballistic-resistant laminate structure wasconstructed of high performance fibers without using resins to hold thefibers together. Instead of resin, thermoplastic film was bonded toouter surfaces of two cross-plied layers of unidirectional fibers tohold the fibers in place. The film did not penetrate into the fibers. Asufficient amount of film resided between the bonded layers to adherethe layers together to form a sheet. Bonding the two layers ofunidirectional fibers cross-plied to one another was necessary to meetstructural requirements of the ballistic-resistant panel, such as impactforce distribution. The individual sheets were placed loosely in afabric envelope of an armored garment to form a ballistic-resistantpanel.

SUMMARY

A ballistic-resistant laminate assembly is provided that overcomesdrawbacks experienced in the prior art and achieves other benefits. Oneaspect of the invention provides a ballistic-resistant laminate assemblyhaving a first layer with a plurality of ballistic-resistant fiberstrands positioned adjacent to each other, a plurality of first bondingstrips, and a plurality of second bonding strips. The first bondingstrips are spaced apart from each other by a selected distance and areat a first orientation with the fiber strands. The second bonding stripsare cross-plied relative to the first bonding strips to form abi-directional array of bonding strips connected to the fiber strands.The second bonding strips are spaced apart from each other by a selecteddistance and are connected to the fiber strands at a predetermined anglerelative to the fiber strands. In one embodiment, the first and secondbonding fibers include ballistic-resistant fibers coated with anadhesive material. In one embodiment, the first and second bondingstrips are bonding fibers configured in a woven arrangement with thefiber strands. A first laminate film is positioned on one side of thefiber strands and bonded to the first layer. A second laminate film ispositioned adjacent to a side of the fiber strands opposite the firstlaminate film.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a plan view of a ballistic-resistant fiber panel withballistic-resistant fiber strands and bonding fibers connected to thefiber strands according to one embodiment of the invention.

FIG. 2A is a plan view of a ballistic-resistant fiber panel withballistic-resistant fiber strands and an array of bi-directional bondingfibers connected to the fibers in accordance with another embodiment ofthe invention.

FIG. 2B is a plan view of a ballistic-resistant fiber panel inaccordance with another embodiment of the invention.

FIG. 2C is a plan view of a ballistic-resistant fiber panel inaccordance with another embodiment of the invention.

FIG. 2D is a plan view of a ballistic-resistant fiber panel inaccordance with yet another embodiment of the invention.

FIG. 3 is a partial, exploded isometric view of one embodiment includingthermoplastic sheets laminating the ballistic-resistant fiber panel ofFIG. 1.

FIG. 4 is a partial, exploded isometric view of another embodiment of alaminated ballistic-resistant fiber panel without interwoven bondingfibers.

FIG. 5 is a partial, exploded isometric view of another embodiment of alaminated fiber panel including first and second sets of laminatedballistic-resistant fiber panels cross-plied relative to each together.

FIG. 6 is a partial, exploded isometric view of yet another embodimentof a laminated fiber panel with alternating layers of laminatedballistic-resistant fibers and laminate film.

FIG. 7 is a partial, exploded isometric view of another embodiment oflayers of laminated ballistic-resistant fibers and laminate films.

FIG. 8 is a partial isometric view of several laminatedballistic-resistant fiber panels stitched together to form a packetunder one embodiment of the invention.

FIG. 9 is a partial isometric view of another embodiment of severallaminated ballistic-resistant fiber panels stitched together.

FIG. 10 is a partial, exploded isometric view of yet another embodimentof several stitched-together packets of laminated ballistic-resistantfiber panels.

FIG. 11 is an armored body garment under one embodiment of theinvention.

FIG. 12 is a partial, exploded isometric view of another embodimenthaving a plurality of ballistic-resistant fiber panels joined together.

DETAILED DESCRIPTION

The inventors have found limitations and inefficiencies with respect tothe performance and to the manufacturing of the prior artballistic-resistant panels. The prior art laminated panels gavestructure to the unidirectional fibers and served to prohibit adjacentsheets from sticking together, but they also facilitated movementbetween the sheets. Thus, the initial impact from, e.g., a bullet to aballistic-resistant panel comprised of loose laminated sheets displacedand rotated the sheets within the pocket such that the anti-ballisticcharacteristics were compromised for subsequent bullets. Additionally,the impact from the bullet bunched and pulled the individual fiberstrands in the sheets and further degraded the integrity of theballistic panel.

When an armor vest is tested in accordance with nationally recognizedstandards, the vest is shot six times at a pre-established distance andin a specific shot pattern. The inventors found with the prior art that,when the bullet pulled the fibers toward entry, the bullet significantlyweakened the areas that fibers were pulled from such that by the fourthand fifth shots, bullets penetrated a raised weakened strike area.Further, in the absence of resins or adhesives, the number of fibers perinch in a panel must be reduced to get opposing laminated sheets to fusetogether. Increasing the density of the fibers to improve ballisticperformance resulted in a panel that delaminated. To form the prior artsheets, fiber spools were unwound as thermoplastic sheets simultaneouslylaminated the fibers to provide alternating layers of fibers andthermoplastic sheets. It was not always feasible, economical, orballistically prudent to simultaneously bond the thermoplastic film onone side of the unspooling fibers. Without the thermoplastic film,however, the unspooled fibers lacked structure and collapsed.

Under one aspect of the invention, a ballistic-resistant fiber panelincludes a plurality of ballistic-resistant fiber strands and bondingstrips, such as a plurality of bonding fibers connected to the fiberstrands. Under another aspect of the invention, two thermoplastic sheetslaminate the fiber panel between them. Under another aspect, one set ofbonding strips is connected to the fiber strands at one predeterminedangle, and a second set of bonding strips at another angle relative tofiber strands is cross-plied with the first bonding strips to form anarray of bi-directional bonding strips connected to theballistic-resistant fiber strands. Under yet another aspect of theinvention, several of the laminated ballistic-resistant fiber panels arestitched or otherwise bound together to form packets. Methods forforming or securing ballistic-resistant fiber strands in sheet form aredescribed in detail below. In the following description, numerousspecific details are provided, such as specific uses, fiberorientations, numbers of layers, etc., to provide a thoroughunderstanding of embodiments of the invention. One skilled in therelevant art will readily recognize that the invention can be practicedwithout one or more of the specific details. In other instances,well-known structures or operations are not shown or described in detailto avoid obscuring aspects of the invention.

As illustrated in FIG. 1, a flexible ballistic-resistant fiber panel 110includes the bonding strips formed by bonding fibers 130 interwoven withstrands of ballistic-resistant fibers 120. As the ballistic-resistantfibers 120 are unspooled, they may be passed through a comb guide wherethe ballistic-resistant fibers are further paralleled and spaced into apredetermined uniform density. In one embodiment, theballistic-resistant fibers 120 are aramid fibers, with a 1000 denierfiber construction and approximately 17 ends/inch untwisted tows sheetconstruction. In another embodiment, the ballistic-resistant fibers 120are aramid fibers, with a 840 denier fiber construction andapproximately 20 ends/inch unidirectional untwisted tows sheetconstruction. In other embodiments, the ballistic-resistant fibers 120can be high performance fibers having a tensile strength of at least 9grams/denier.

As the ballistic-resistant fibers 120 are unspooled to form a fiberpanel 110, the bonding fibers 130 are interwoven at an angle withrespect to the ballistic-resistant fibers 120. In the illustrativeembodiment, the bonding fibers 130 are interwoven perpendicular to theballistic-resistant fibers 120 on approximately one-inch centers.Preferably the bonding fibers 130 are spaced one-half inch to twoinches, and more preferably, the bonding fibers 130 are evenly spacedone inch apart. The bonding fibers 130 are positioned to alternativelygo under and over adjacent sets of the ballistic-resistant fibers 120 ina woven arrangement, thereby providing a bi-directional, ormultidirectional arrangement of fibers. In selected embodiments, thesets of ballistic-resistant fibers 120 that the bonding fibers go overor under have a width of about one-half inch to two inches, so as tosubstantially correspond to the distance between adjacent bonding fibers130.

In one embodiment, the bonding fibers 130 are an ethylene vinyl acetatewith a polyester core. The coating may be made of natural or manmadepolymers, copolymers, waxes, or mixtures thereof. The coating isconfigured to at least partially coat and securely adhere to theballistic-resistant fibers 120, thereby substantially holding theballistic-resistant fibers together. Representative examples include,but do not limit the scope of use to, the following: styrene, butadiene,poly-butadiene, polyvinylchloride, polyethylene, polypropylene,polyvinyl acetate (plasticized), acrylics, polyvinyl pyrrolidenecompounds, natural latex, paraffin wax of the hot melt type, casein,carboxy cellulose esters, and ethers. The core may alternatively beconstructed out of nylon, cotton, or aramid fiber or other highperformance fibers having a tensile strength of at least 9 grams/denier.In other embodiments, the bonding fibers 130 are constructed of aballistic-resistant fiber, such as an aramid fiber, with a coating ofheat- or pressure-sensitive adhesive that will adhere to theballistic-resistant fibers 120. The bonding fibers 130 can besubstantially the same as the ballistic-resistant fibers 120.Alternately, the bonding fibers 130 can be a different size than theballistic-resistant fiber 120.

After the bonding fibers 130 are interwoven with the ballistic-resistantfibers 120, they are bonded into a ballistic-resistant oriented fiberpanel 110, for example, with heat and pressure from either static heator an autoclave. The desired temperature range during heating ispreferably up to 500 degree F., more preferably in the range of 225-375degree F., and most preferably 265 degree F. under 45 psi of pressure.In addition to heat bonding the bonding fibers 130 to theballistic-resistant fibers 120, bonding can be effected by other methodsdepending upon the particular chemical composition of the fiber'scoating. For example, bonding can be done by moisture, the use oforganic solvents, high-pressure alone, or contact pressure. Such bondingtechniques, however, should not adversely affect the ballistic-resistantfibers 120 or destroy the configuration of the fibers that the bondingfibers 130 are to reinforce. Further, the coating of the bonding fibers130 must bond with whatever surface coating or laminate is to be appliedto the ballistic-resistant fiber panel 110.

Interweaving the bonding fibers 130 with the ballistic-resistant fibers120 allows the fiber panel 110 to be handled, transported, and processedeither at a different location or at a later time. This feature providesadvantages, including both efficiency and economy. Under traditionalmanufacturing methods, it was necessary to secure the thermoplastic filmonto one side of the fibers at the same time the ballistic-resistantfibers were unspooled to provide structure for the ballistic-resistantfibers and to preserve the sheet configuration of the fibers. Thebonding fibers 130 provide this structure to the ballistic-resistantfibers 120. Thus, a thermoplastic film may be laminated to theballistic-resistant fibers 120 either at the same time as theballistic-resistant fibers 120 are unspooled or at a later time.

FIG. 2A is a plan view of a ballistic-resistant fiber panel 200, with awoven array of bi-directional bonding fibers 130 connected to theballistic-resistant fibers 120 in accordance with another embodiment ofthe invention. In the illustrated embodiment, the bonding fibers 130include a first set of spaced-apart bonding fibers 228 generallyperpendicular to the ballistic-resistant fibers 120, although thebonding fibers can be oriented at another selected angle relative to theballistic-resistant fibers. The fiber panel 200 also has a second set ofspaced-apart bonding fibers 230 substantially parallel with theballistic-resistant fibers 120. The first set of bonding fibers 230 iscross-plied and arranged in a woven configuration with the second set ofbonding fibers 228 and with the ballistic-resistant fibers 120. Thecross-plied bonding fibers 228 and 230 form a bi-directional array 210of bonding fibers that hold the ballistic-resistant fibers 120 in aparallel orientation. The fiber panel 200 can then be handled andmanipulated in the manufacturing processes to form ballistic-resistantpanels or the like. In one embodiment, the first and second sets ofbonding fibers 228 and 230 are aramid fibers coated with selectedadhesive, such as a heat and/or pressure sensitive adhesive.

In another embodiment shown in FIG. 2B, the ballistic-resistant fiberpanel 200 has an array of bi-directional bonding strips 1130 connectedto the ballistic-resistant fibers 120. In the illustrated embodiment,the bonding strips 1130 include a first set of spaced-apart bondingstrips 1228 generally perpendicular to the ballistic-resistant fibers120, although the bonding strips can be oriented at another selectedangle relative to the ballistic-resistant fibers. The fiber panel 200also has a second set of spaced-apart bonding strips 1230 substantiallyparallel with the ballistic-resistant fibers 120. The first set ofbonding strips 1230 is cross-plied with the second set of bonding strips1228 and with the ballistic-resistant fibers 120. In one embodiment, thefirst and second sets of bonding strips 1228 and 1230 are lengths ofheat and/or pressure sensitive adhesive applied to the ballisticresistant fibers 120.

The bonding strips 1228 and 1230 of one embodiment can be applied theballistic-resistant fibers 120 while the ballistic resistant fibers arebeing unspooled and arranged in the parallel configuration, or thebonding strips can be applied after the ballistic-resistant fibers havebeen arranged in the parallel configuration. The cross-plied bondingstrips 1228 and 1230 form a bi-directional array 1210 of bonding stripsthat hold the ballistic-resistant fibers 120 in a parallel orientation.The fiber panel 200 can then be handled and manipulated in themanufacturing processes to form ballistic-resistant panels or the like.The bonding strips 1228 and 1230 of different embodiments can be fibrousor non-fibrous. The bonding strips 1228 and 1230 in selected embodimentscan be applied in a liquid or semi-liquid format to form spaced-apartstripes of bonding material that act, inter alia, to hold theballistic-resistant fibers 120 together. In other embodiments thebonding strips 1228 and 1230 can be elongated lengths of material, suchas a tape-like material, applied to the ballistic resistant fibers 120during or after the ballistic-resistant fibers are arranged in theparallel configuration.

In another embodiment shown in FIG. 2C, the ballistic-resistant fiberpanel 200 has the first set of spaced-apart bonding fibers 228 orientedat an angle relative to the ballistic-resistant fibers 120. The bondingfibers 228 in the illustrated embodiment are made of ballistic-resistantfibers, such as aramid fibers, coated with a selected heat and/orpressure sensitive adhesive. In one embodiment, the angle of the firstset of bonding fibers 228 is generally between 0 degrees and 90 degrees.In another embodiment, the angle is generally between approximately 30degrees and 60 degrees, inclusive. The first set of bonding fibers 228can be woven with the ballistic-resistant fibers 120. The second set ofspaced-apart bonding fibers 230 are oriented at second angle relative tothe ballistic-resistant fibers 120 and are oriented at an angle relativeto the first set of bonding fibers 228. Accordingly, the first andsecond sets of bonding fibers 228 and 230 provide a multi-axial array ofbonding fibers.

The bonding fibers 230 in the second set are also made ofballistic-resistant fibers, such as aramid fibers, coated with aselected heat and/or pressure sensitive adhesive. The bonding fibers 230in this embodiment are not perpendicular or parallel to theballistic-resistant fibers 120. In one embodiment, the angle of thesecond set of bonding fibers 230 relative to the ballistic-resistantfibers 120 is between 90 degrees and 180 degrees. In another embodiment,the angle is between approximately 120 degrees and 150 degrees,inclusive. In one embodiment, the second set of bonding fibers 230 arewoven with the ballistic-resistant fibers 120 and with the first set ofbonding fibers 228. The first and second sets of bonding fibers 228 and230 can be perpendicularly oriented relative to each other, or they canbe oriented at other angles to provide the bi-directional woven array ofbonding fibers. Accordingly, the ballistic-resistant fibers and thefirst and second sets of bonding fibers 228 and 230 in the illustratedembodiment form a triaxial array of ballistic resistant fibers that formthe ballistic-resistant fiber panel.

In another embodiment, a ballistic-resistant panel is formed with thebonding fibers 120 and three or more sets of spaced apart bonding fibersmade of ballistic-resistant fibers coated with a selected heat and/orpressure-sensitive adhesive. Each set of these spaced apart bondingfibers are angularly offset relative to each other and relative to theballistic-resistant fibers 120. Accordingly, the ballistic-resistantpanel is formed with a multi-axial array of ballistic-resistant bondingfibers.

In one embodiment, the ballistic-resistant bonding fibers 228 and 230can be made of the same material as the ballistic-resistant fibers 120and coated with a selected adhesive coating. Alternatively, the bondingfibers 228 and 230 can be made of an adhesive-coated ballistic-resistantmaterial having performance characteristics different than theballistic-resistant fibers 120. As an example, the ballistic-resistantbonding fibers 228 and 230 can be coated aramid fibers with a smallerdenier fiber construction and smaller diameter than the denier fiberconstruction and diameter of the ballistic-resistant fibers 120.

In yet another embodiment shown in FIG. 2D, the ballistic-resistantfiber panel 200 has a first set of spaced-apart bonding strips 1228oriented at an angle relative to the ballistic-resistant fibers 120. Thebonding strips 1228 in the illustrated embodiment contain a selectedheat and/or pressure sensitive adhesive. In one embodiment, the angle ofthe first set of bonding strips 1228 is generally between 0 degrees and90 degrees. In another embodiment, the angle is generally betweenapproximately 30 degrees and 60 degrees, inclusive. The first set ofbonding strips 1228 can be applied during or after theballistic-resistant fibers 120 are arranged in the parallelconfiguration. The second set of spaced-apart bonding strips 1230 areoriented at second angle relative to the ballistic-resistant fibers 120and are oriented at an angle relative to the first set of bonding strips1228. Accordingly, the first and second sets of bonding strips 1228 and1230 provide a multi-axial array of bonding strips.

As illustrated in FIG. 3, lower and upper thermoplastic films 340 and342, respectively, are provided on bottom and top sides of the singlefiber panel 110, and then secured or laminated thereto so that theballistic-resistant fibers are securely sandwiched between the films toform a flexible, ballistic-resistant sheet 300. In one embodiment, thethermoplastic films 340 and 342 are extremely thin, typically less than0.35 mils, to maintain the flexibility of the laminatedballistic-resistant sheet 300. Alternatively, thicker laminate films upto approximately 0.5 mils may be used to form a laminated fiber sheet ofgreater rigidity.

In one embodiment, the laminate film will coat the exterior surfaces ofthe ballistic-resistant fibers 120 to encapsulate them, but will notimpregnate the fibers. Sufficient plasticized film material flowsbetween adjacent ballistic-resistant fibers 120 to bond thethermoplastics films 340 and 342 to the ballistic-resistant fibers. Thethermoplastic films 340 and 342 may be a polyethylene film. Due to thestructure provided by bonding fibers 130 and 230 (shown in phantom linesin FIG. 3), the thermoplastic films 340 and 342 may be laminated overthe ballistic-resistant fibers 120 either as the ballistic-resistantfibers are unspooled and interwoven with the bonding fibers 130 or at alater time. The thermoplastic films 240 and 242 laminate to each side ofthe ballistic-resistant fibers 120 to form the flexible, laminated,ballistic-resistant fiber sheet 300. The flexible sheet 300 may be usedindividually or may be combined with other sheets as described below, toform a variety of items, including ballistic-resistant panels.

The bonding fibers 130 further provide structure to which thethermoplastic films 340 and 342 can bond. Because the thermoplasticfilms 340 and 342 bond with the interwoven bonding fibers 130, the fiberpanel 110 may contain a greater density of ballistic-resistant fibers120. The bonding fibers 130 of these embodiments thus provide at leasttwo functions: the bonding fibers help prevent the ballistic-resistantfiber panel from spreading or delaminating before and after thethermoplastic films 340 and 342 are laminated over theballistic-resistant fibers 120, and the bonding fibers provide the panelenhanced buoyant characteristics. The greater density of theballistic-resistant fibers 120 in the panel combine with the bondingfibers 130 to form interstitial air pockets 344 trapped between thelaminate films 340 and 342.

The bonding fibers 130 allow the density of the ballistic-resistantfibers 120 to be maximized by giving the fiber panel 110 furtherstructure while preventing delamination of the laminated fiber sheet 300by bonding with the thermoplastic film. The bond between thethermoplastic sheets 340 and 342 and the bonding fibers 130 createequally spaced sealed interstitial air pockets that, when used in aballistic panel, produce buoyant ballistic panels. In the embodimentsshown in FIGS. 2A and 2B having the bi-directional woven array 210 ofbonding fibers, both sets of the bonding fibers 228 and 230 act with thethermoplastic films 340 and 342 shown in FIG. 3 to form the interstitialair pockets 344 that provide the ballistic-resistant sheet 300 with apositive buoyancy. Accordingly, a plurality of ballistic-resistantsheets 300 can be joined together (as discussed in greater detail below)to form a flexible, ballistic-resistant panel having positive buoyancy.The buoyant flexible, ballistic-resistant panel can be used to make aselected assembly, such as a ballistic-resistant garment or the like.

The fiber panels 110, 200, and 300 discussed above are substantiallyflexible ballistic-resistant panels. In other embodiments, sufficientheat or heat with sufficient pressure can be applied to thethermoplastic films 340 and 342 for a sufficient duration to melt one orboth of the thermoplastic films 340 and 342 into the ballistic-resistantfiber 120 to form a semi-rigid or rigid structure. Before heating thethermoplastic films 340 and 342, the laminated ballistic-resistant fibersheet 300 may be configured into any variety of shapes. This semi-rigidor rigid structure may be used alone or may be used in combination withother panels to form any variety of items, including, but not limitedto, cargo boxes, storage boxes, aircraft containers, water skis, snowskis, hockey sticks, vehicle bodies such as boat hulls, and protectiveelements such as helmets for racing, military use, or bicycling.

As illustrated in FIG. 4, another embodiment includes a fiber panel 410of ballistic-resistant fibers 120 with lower and upper sheets ofthermoplastic films 340 and 342 provided on a bottom and top surface ofthe fiber panel to form a flexible laminated ballistic-resistant fibersheet 400. The ballistic-resistant fiber panel 410 laminated on bothsides by thermoplastic films 340 and 342 provides a fiber sheet 400 withmaximum flexibility while providing sufficient structure to preventdegradation of the fiber sheet's configuration. This ballistic-resistantfiber panel 410 may be used individually or in combination with otherfiber panels disclosed herein. Alternatively, the thermoplastic films340 and 342 may be heated such that the thermoplastic films will meltand encapsulate or impregnate the individual fiber strands 120 resultingin a substantially rigid sheet (not shown).

The decision to produce either a rigid or a flexible fiber sheet istypically dictated by the end use of the fiber sheet 400. Multiplepliable panels or sheets 110, 200, 300, or 400 can be used to formflexible ballistic-resistant panels used in a wearable garment, whileproviding ballistic protection to the wearer. Several sheets 110, 200,300, or 400 in a rigid configuration can be used for otherballistic-related structures, such as helmets configured to fit thewearer's head.

As illustrated in FIG. 5, another embodiment provides aballistic-resistant, laminated panel 500 that has a first laminatedfiber sheet 510 with ballistic-resistant fibers 120 oriented in a firstdirection (as illustrated in FIG. 1), and a second laminatedballistic-resistant fiber sheet 512 having ballistic-resistant fibers120 oriented in a second direction. As illustrated, the sheets 510 and512 each include bonding fibers 130 positioned substantiallyperpendicular to the ballistic-resistant fibers 120 and interwoven withthe ballistic-resistant fibers 120. In the embodiments providing thearray 210 of bi-directional bonding fibers 130 and 230, the cross-pliedbonding fibers are substantially perpendicular to each other.Accordingly, one set of bonding fibers 230 is substantially parallel tothe fiber strands 120, and the other set of bonding fibers 130 issubstantially perpendicular to the fiber strands. In one embodiment, thebonding fibers 230 can be ballistic-resistant fibers angularly offsetrelative to the fiber strands 120, as discussed above with reference toFIG. 28.

In one embodiment, the bonding fibers 130 are visual indicators thatallow for easy confirmation that adjacent fiber panels 110 arecross-plied relative to each other. As an example, the bonding fibers130 parallel to the ballistic-resistant fibers 120 in each laminatedsheet 512 are colored differently than the ballistic-resistant fibers.Accordingly, when the two laminated sheets 510 and 512 are adjacent toeach other, a person can quickly and easily determine whether theballistic-resistant fibers 120 are cross-plied by looking at therelative orientation of the colored bonding fibers. If the coloredbonding fibers 130 of each adjacent laminated sheet 510/512 arecross-plied relative to each other, the person knows that theballistic-resistant fibers are properly cross-plied. In one embodimentadjacent fiber panels 110 can have different colored bonding fibers 130,and in alternate embodiments the bonding fibers in each fiber panel canhave the same color although different from the ballistic-resistantfibers 120. In the embodiment having the bi-directional array 210 ofbonding fibers 130, the bonding fibers can be configured so that some orall of the bonding fibers 230 parallel to the ballistic-resistant fibers120 have a different color than the cross-plied bonding fibers 228 inthat fiber panel 110.

The laminated panel assembly 500 of the illustrated embodiment hasmultiple cross-plied fiber panels 110, and each fiber panel 110 islaminated between lower and upper laminate films 340 and 342, therebyforming laminated sheets 510 and 512 with a configuration of film/fiberpanel/film. Multiple laminated sheets 510, 512 can be joined togethersuch that the ballistic-resistant fibers 120 of adjacent layers arecross-plied relative to each other. The resulting laminated sheet 500has a lamination configuration of film/fiber panel/film/film/fiberpanel/film. . . . The multiple laminated layers 510, 512 can be retainedtogether by an adhesive provided between layers, or by stitching thelayers together or by other laminating techniques. As discussed above,the bonding fibers 130 provide structure to the ballistic-resistantfibers 120 and allow the panel 110 to be manufactured without thethermoplastic film 340 or 342. Alternatively, if the thermoplastic film340 or 342 is bonded to either a first or a second surface when theballistic-resistant fibers 120 are unspooled and combined with thebonding fibers 130 in the weave pattern to form the ballistic-resistantpanel 110, then the thermoplastic film may be used to provide additionalstructure to the panel.

When the ballistic-resistant fibers 120 are combined with the bondingfibers 130 in the weave pattern, layered on or between thermoplasticfilms 340 and 342, and laminated to produce a flexible sheet 500, theresulting flexible sheet is easy to handle without damaging, loosening,or substantially degrading the effectiveness of the ballistic-resistantfibers. The flexible, laminated sheet 500 is also quite buoyant becauseof the interstitial air pockets 344 trapped within the sheet between thelaminate films 340 and 342.

FIG. 6 is a partial exploded isometric view of an alternate embodimentof a laminated fiber panel sheet 600. The laminated sheet 600 includes afirst fiber panel 110 with the ballistic-resistant fibers 120 aligned inone direction. A second fiber panel 110 is cross-plied with the firstfiber panel so that the ballistic-resistant fibers 120 of the secondpanel are substantially perpendicular to the ballistic-resistant fibersof the first panel. Accordingly, the laminated sheet 600 provides thecross-plied layers of the ballistic-resistant fibers 120. In otherembodiments, the fiber panels 110 can be oriented with theballistic-resistant fibers 120 at selected angles relative to eachother, and not necessarily limited to a perpendicular orientation. Inother embodiments, additional fiber panels 110 can be provided in thelaminated sheet 600, and each fiber panel 110 can be selectivelyoriented in a cross-plied configuration relative to the adjacent layersas desired.

In the laminated sheet 600 as illustrated in FIG. 6, the first fiberpanel 602 is bonded or otherwise adhered to a lower laminate film 606such that the lower laminate film is attached to the bottom surface ofthe first fiber panel. A middle laminate film 608 is attached to the topsurface of the first fiber panel 602, so that the first fiber panel issandwiched between the lower and middle laminate films 606 and 608. Thesecond fiber panel 604 is adhered along its bottom surface to the middlelaminate film 608 so the middle laminate film is sandwiched between thefirst and second fiber panels 602 and 604. An upper laminate film 610 isadhered to the top surface of the second fiber panel 604. Accordingly,the structure of the laminated sheet 600 provides alternating layers offilm and fiber panel to provide a configuration of film/fiberpanel/film/fiber panel/film/ . . . with each successive fiber panel 110being cross-plied relative to its adjacent fiber panels. Each of thefiber panels 602/604 can have the bonding fibers 130 or the array 210 ofthe bi-directional bonding fibers.

FIG. 7 is a partial exploded isometric view of another embodiment of alaminated sheet 700. The laminated sheet 700 includes a firstballistic-resistant fiber panel 702 directly attached to a secondballistic-resistant fiber panel 704 that has the ballistic-resistantfibers 120 cross-plied relative to the ballistic-resistant fibers of thefirst fiber panel. The bonding fibers 130/230 provide adhesivecharacteristics that at least partially bond the first and second fiberpanels 702 and 704 together. The first and second laminated panels 702and 704 can be provided with one set of spaced-apart bonding fibers 130at a selected angle relative to the ballistic-resistant fibers 120(e.g., perpendicular). In other embodiments, fiber panels 702 caninclude the array 210 of bonding fibers 130, as discussed above.

The laminated sheet 700 illustrated in FIG. 7 has a bottom laminate film340 attached to the bottom surface of the first fiber panel 702, suchthat first fiber panel is between the laminate film and the second fiberpanel 704. The laminated sheet 700 also has a top laminate film 342attached to the top surface of the second fiber panel 704, such that thesecond fiber panel is between the top laminate film and the first fiberpanel 702. Accordingly, the laminated sheet 700 has a laminationconfiguration of film\fiber panel\fiber panel\film. The laminated sheet700 illustrated in FIG. 7 shows the use of only two laminated panels 702and 704, although alternate embodiments can provide additional layers offiber panels between the laminate films 340 and 342. The laminated sheet700 can be a flexible sheet, but in other embodiments, the laminatedsheet can be a semi-rigid or rigid structure.

FIG. 8 is an isometric view of a stack of layers 800 of laminated sheetsstacked on top of one another with the ballistic-resistant fibers 120 ofeach fiber panel 110 selectively oriented relative to theballistic-resistant fibers of adjacent fiber panels, such as parallel,perpendicular, or at other angles. The stack of layers 800 can be madeup of multiple layers of any one of the laminated fiber sheets 300, 400,500, 600, and/or 700 discussed above, or any mixed combination of thelaminated fiber sheets. The stack of layers 800 is secured together bystitches 810 to form a packet 820.

In another embodiment, adjacent sheets 300/400/500/600/700 can besecured together with an adhesive provided between the adjacent layers.The adhesive can be applied in selected patterns on the facing surfaces,so as to control the stiffness or rigidity of the resulting stack oflayers 800. The stack of layers 800 adhered together can also bestitched together at selected locations or patterns as needed for theparticular application for which the packet 820 is to be used. Further,any one of the sheets illustrated in FIGS. 1-7 may be used in anycombination to form the packet 820. Specifically, when using theballistic-resistant laminated sheets 500 illustrated in FIG. 5 to formthe packet 820, preferably three to eight sheets are sewn together toform the packet 820, more preferably four to six panels, and mostpreferably five panels are used to form the packet. When using theballistic-resistant fiber sheets 300 or 400 (FIG. 3 or 4) to form thepacket 820 for use in a ballistic-resistant panel assembly, the sheetsare placed such that the orientation of ballistic-resistant fibers isrotated a selected angle with respect to adjacent sheets.

Stitching the layers 800 together to form the packet 820 providesimproved resistance to ballistic penetration in a ballistic panel withfewer total fiber panels required, as described below. In oneembodiment, preferably four to ten packets of laminated sheets 500 areused to form a ballistic panel, more preferably four to eight packetsand most preferably six packets are used to form a ballistic-resistantpacket 820. When a bullet hits a ballistic-resistant panel 820, thebullet penetrates the initial layers 500 and the impact force of thebullet displaces secondary layers. When the ballistic-resistant panel820 is made up of several individual ballistic-resistant fiber sheets orpanels, the force of the bullet causes some fibers in the panel to pushapart and separate and other fibers at the tip of the bullet to bunch.Adjacent fibers that the bullet does not actually penetrate are pulledout of position and weakened by the impact force of the bullet. Thiscreates a path of reduced resistance through the panel. The result isthat the integrity of the ballistic-resistant panel is significantlyimpaired after the first impact. Packets of ballistic-resistant fiberlayers retain the benefit that the movement between the individuallayers allows, i.e., shifting the bullet off course and diffusing thestraight-line penetration of the bullet, while decreasing thepenetration and the bunching caused by the bullet. The packets act likeindividual panels within the ballistic-resistant panel in that eachindividual packet acts independently of the adjacent packet. Thus thebullet's trajectory angles at each packet so that it does not create apath through the panel.

Fewer layers are used to form a ballistic-resistant panel of equivalentcharacteristics compared to prior systems; therefore, the resultantpanel is more flexible and lighter in weight. When a bullet impacts aballistic-resistant panel, the panel is subject to both the impact forceof the bullet and a reverberating energy wave sent out ahead of thebullet. The components of the packet of this embodiment combine toprovide a more efficient ballistic-resistant panel. Components includeany one of or a combination of the following: density of theballistic-resistant fibers in the panel, bonding thread, the cross-pliedpositioning of the fiber panels, thermoplastic films, the laminatedfiber panels, and laminated panel assemblies stitched together inpackets. The interaction between the individual packets works in acooperative effort to provide an improved ballistic-resistant panel.Among other things, sewing the layers in a packet maximizes theanti-ballistic properties of the individual layers such that theresultant packet is stronger than the sum of the individual layers.Additionally, because fewer layers are required, the ballistic-resistantpanel is less expensive to manufacture.

Stitching the layers 800 to form the packet 820 may be done by anyvariety of stitching patterns and is illustrated in FIG. 8 as a diamondpattern. An alternative pattern includes vertical stitchingperpendicular to the ballistic-resistant fibers. Vertical stitchinghelps prevent the fibers from pulling side to side. Vertical stitchesare preferably evenly spaced, more preferably evenly spaced 2″-4″ apartand most preferably evenly spaced 3″ apart. Stitching patterns may alsoinclude perimeter stitching, continuous and noncontinuous patterns, andany other variety of stitching patterns. In addition to stitching tosecure the sheets together to form a packet, any one of a number ofdevices, including, but not limited to, the following may be used:staples (permanent plastic or metal); dry or wet adhesive applieddirectly or on strips such as double-sided tape; various patterns of bartacks; interlocking tabs in the sheets themselves or slots in thelaminate; heat-fusible thread on the exterior of select sheets; stackingtwo or more thermoplastic films and applying heat while pressing themtogether and taking advantage of the “sticky” properties of the filmelement of the laminate; fine Velcro or similar hook and loop materialbetween the layers of sheets, snaps, any permutations and/orcombinations of all the above devices; induced static electrical charge;and interwoven magnetic material. Additionally, a wide variety ofmaterials may be used for the stitching thread, including natural andmanmade fiber threads, polymer-based threads (such as fishing line),fine steel or other metal or composite or alloy wire, and racket sportsstring (including natural, such as catgut, and synthetic materials).

FIG. 9 illustrates another embodiment of a packet 900 of severalballistic-resistant fiber sheets affixed together. As discussed above,any combination of sheets may be used to form the packet 900, including,but not limited to, this illustrated combination layering of differentsheets 500, 400, 300, 400 and 500. As the individual sheetconfigurations have specific features or strengths, the positioning ofthe sheets within the packet will serve to highlight those features orstrengths.

As illustrated in FIG. 10, the packets 820 or 900 are combined to form aballistic-resistant panel 1000. As is further illustrated in FIG. 11,one or more packets 820 or 900 can be bundled together and inserted inpockets 1100 to form a ballistic-resistant panel 1000. Thisballistic-resistant panel 1000 may be used as illustrated in a structuresuch as a vest 1150. The packets 820 or 900 increase ballistic-resistantefficiency by helping to hold the sheets in position. Traditionally, thefirst impact or shot to the ballistic-resistant panel 1000 causeddisplacement and rotation of the sheets, which resulted in a lessefficient ballistic-resistant panel for second or subsequent sheets. Thestitching 810 or otherwise securing the individual sheets to formpackets 820 or 900, and then bundling the packets 820 or 900 together toform a ballistic-resistant panel 1000, reduces the shifting and rotationcaused by the initial shot.

FIG. 12 is a partially exploded isometric view of a ballistic-resistantpanel 1200 in accordance with another embodiment. Theballistic-resistant panel 1200 is formed by a plurality ofballistic-resistant fiber sheets 1202. Laminate films are not providedbetween the ballistic-resistant sheets 1202 in this embodiment. Thesheets 1202 have the plurality of ballistic-resistant fibers 120 a setof spaced-apart bonding fibers 130 woven or bonding strips at a selectedangle relative to the ballistic-resistant fibers. The bonding fibers 130are shown in FIG. 12 at one angle although other angular orientations,including a perpendicular orientation, could be used. The bonding fibers130 can be ballistic-resistant fibers, such as aramid fibers, coatedwith a selected heat and/or pressure sensitive adhesive. In oneembodiment, each ballistic-resistant sheet 1202 also has a second set ofspaced-apart bonding fibers 130 or bonding strips woven with the firstset of bonding fibers and with the ballistic-resistant fibers 120.Accordingly, each ballistic-resistant fiber sheet 1202 is amulti-directional array of fibers.

The ballistic-resistant sheets 1202 are oriented so theballistic-resistant fibers 120 of each sheet is cross-plied at aselected angle relative to the ballistic-resistant fibers of theadjacent sheets. The ballistic-resistant fibers 120 of adjacent sheetscan be cross-plied approximately a 90 degree orientation, althoughangular orientations can be used. When the ballistic-resistant sheets1202 are positioned together to form the panel 1200, the bonding fibers130 in each sheet bond to the ballistic-resistant fibers 120 of thesheet and also to the ballistic-resistant fibers and/or the bondingfibers of the adjacent sheets. The bonding fibers 130 securely retainthe adjacent ballistic-resistant sheets 1202 together while maintainingthe desired degree of flexibility or rigidity of the ballistic-resistantpanel 1200. The plurality of ballistic-resistant sheets 1202 inalternate embodiments can also be stitched together, as discussed above.

The impact of the bullet indents the ballistic-resistant panel andcauses some of the fibers in the ballistic-resistant panel to compact atthe front of the bullet while stretching and pulling other fibers out ofposition as the bullet moves through the ballistic-resistant panel.Additionally, the indentation from the force of the bullet in theballistic-resistant panel in one location causes a resulting protrusionof the panel's flat surface surrounding the indentation. This protrusioncan buckle the surface of the entire panel depending on the entrylocation of the bullet. This buckling creates an air pocket between thepanel and the wearer's chest, which in turn impacts the integrity of theentire ballistic-resistant panel.

The various embodiments described above can be combined to providefurther embodiments. All of the above U.S. patents and applications areincorporated by reference. Aspects of the invention can be modified, ifnecessary, to employ the systems, circuits, and concepts of the variouspatents and applications described above to provide yet furtherembodiments of the invention.

These and other changes can be made to the invention in light of theabove detailed description. In general, in the following claims, theterms used should not be construed to limit the invention to thespecific embodiments disclosed in the specification and the claims, butshould be construed to include all ballistic-resistant fiber sheets thatoperate under the claims. Accordingly, the invention is not limited bythe disclosure, but instead its scope is to be determined entirely bythe following claims.

1-63. (canceled)
 64. A ballistic-resistant laminate assembly,comprising: a first layer comprising a plurality of substantiallyunidirectional ballistic-resistant fiber strands positioned adjacent toeach other in a substantially parallel orientation, and a plurality ofadhesive bonding strips spaced apart from each other and connected tothe plurality of substantially unidirectional ballistic-resistant fiberstrands, the plurality of adhesive bonding strips further comprising apressure sensitive adhesive material and being positioned at apredetermined angle relative to the ballistic-resistant fiber strands; afirst laminate film adhered to the first layer of ballistic-resistantfiber strands, the first layer and the first laminate film forming afirst laminated ballistic-resistant sheet; a second layer having aplurality of unidirectional ballistic-resistant second fiber strandspositioned adjacent to each other in a substantially parallelorientation; and a second laminate film adhered to the second layer ofunidirectional ballistic-resistant fiber strands, the second layer andthe second laminate film forming a second laminated ballistic-resistantsheet connected to the first laminated ballistic-resistant sheet. 65.The assembly of claim 64, wherein the second laminate film is furtherpositioned between the first and second layers of unidirectionalballistic-resistant fiber strands.
 66. The assembly of claim 65, furthercomprising a third laminate film attached to the first layer sandwichingthe first layer of unidirectional ballistic-resistant fiber strandsbetween the first and third laminate films forming a first laminatedlayer; and further comprising a fourth laminate film attached to thesecond layer sandwiching the second layer of unidirectionalballistic-resistant fiber strands between the second and fourth laminatefilms forming a second laminated layer adjacent to the first laminatedlayer.
 67. The assembly of claim 66 wherein at least one of the firstlaminated layer and the second laminated layer further comprises aplurality of substantially sealed interstitial air spaces between thelaminate films, the at least one of the first and second laminatedlayers comprising the plurality of substantially sealed interstitial airspaces further comprising a positive buoyancy.
 68. The assembly of claim64, wherein the unidirectional ballistic-resistant fiber strands furthercomprise aramid fibers.
 69. The assembly of claim 64 wherein theplurality of adhesive bonding strips further comprises a plurality ofadhesive bonding fibers, and further comprising an adhesive materialcoated on the plurality of adhesive bonding fibers.
 70. The assembly ofclaim 69, wherein the adhesive material further comprises a pressuresensitive adhesive material.
 71. The assembly of claim 64, wherein theplurality of adhesive bonding strips further comprises a first pluralityof adhesive bonding strips; further comprising a second plurality ofadhesive bonding strips spaced apart from each other and connected tothe plurality of substantially unidirectional ballistic-resistant fiberstrands at an angle relative to the ballistic-resistant fiber strandsand at an angle relative to the first plurality of adhesive bondingstrips, the second plurality of adhesive bonding strips furthercomprising a pressure sensitive adhesive material.
 72. The assembly ofclaim 71 wherein one of the first and second pluralities of adhesivebonding strips further comprises a plurality of adhesive bonding fibers,the adhesive bonding fibers being coated with an adhesive material. 73.The assembly of claim 72 wherein the adhesive material further comprisesa pressure sensitive adhesive material.
 74. The assembly of claim 64,further comprising stitching connecting the second laminatedballistic-resistant sheet to the first laminated ballistic-resistantsheet.
 75. A ballistic-resistant laminate assembly, comprising: a firstlayer having a plurality of ballistic-resistant fiber strands positionedadjacent to each other, a plurality of first bonding strips comprisingan adhesive material and a plurality of second bonding strips comprisingan adhesive material, the first bonding strips being spaced apart fromeach other by a selected distance and being arranged at a first anglerelative to the ballistic-resistant fiber strands and being connected tothe ballistic-resistant fiber strands, the second bonding strips beingspaced apart from each other by a selected distance and being arrangedat a second angle relative to the ballistic-resistant fiber strands andbeing connected to the ballistic-resistant fiber strands, and the secondbonding strips being cross-plied with the first bonding strips; a firstlaminate film positioned on a first side of the ballistic-resistantfiber strands and bonded to the first layer with one of the first andsecond bonding strips; and a second laminate film positioned a secondside of the ballistic-resistant fiber strands opposite the firstlaminate film.
 76. The assembly of claim 75 wherein the adhesivematerial further comprises a pressure sensitive adhesive material. 77.The assembly of claim 75, wherein the first bonding strips furthercomprise bonding fibers coated with an adhesive material.
 78. Theassembly of claim 76, wherein the second laminate film is bonded to thefirst layer, with the ballistic-resistant fiber strands being laminatedbetween the first and second laminate films.
 79. The assembly of claim78, further comprising interstitial air pockets substantially sealedbetween the first and second laminate films and forming a laminatedballistic-resistant assembly having positive buoyancy.
 80. The assemblyof claim 75, further comprising a second layer formed of a plurality ofballistic-resistant fiber strands positioned adjacent to each other andconnected by a plurality of third bonding strips and a plurality offourth bonding strips, the third bonding strips being spaced apart fromeach other by a selected distance, and the fourth bonding strips beingspaced apart from each other by a selected distance and being arrangedat a second angle relative to the ballistic-resistant fiber strands andbeing connected to the ballistic-resistant fiber strands, and the fourthbonding strips being cross-plied with the third bonding strips; a thirdlaminate film positioned on a first side of the ballistic-resistantfiber strands and bonded to the second layer with one of the third andfourth bonding strips; a fourth laminate film positioned a second sideof the ballistic-resistant fiber strands opposite the third laminatefilm; and stitching connecting the second layer to the first layer. 81.A ballistic-resistant laminate assembly, comprising: a plurality ofballistic-resistant fiber strands; a plurality of first bonding fibersspaced apart from each other and interconnecting the fiber strands, thefirst bonding fibers being oriented at a predetermined angle relative tothe fiber strands; a plurality of second bonding fibers spaced apartfrom each other and connected to the fiber strands and being at apredetermined angle relative to the first bonding fibers, at least thefirst or second bonding fibers being coated with an adhesive material,the first and second bonding fibers forming a bi-directional array ofbonding fibers that hold the fiber strands in a substantially parallelorientation; and a first laminate film adjacent to one side of the fiberstrands and bonded to at least one of the first or second bondingfibers.
 82. The assembly of claim 81, wherein the adhesive materialfurther comprises a pressure sensitive adhesive material.
 83. Theassembly of claim 81, wherein the plurality of first bonding fibersfurther comprises ballistic-resistant fibers.
 84. The assembly of claim81, further comprising a second laminate film, the ballistic-resistantfiber strands and the bonding fibers being laminated and substantiallysealed between the first and second laminate films with interstitial airpockets therebetween to form a laminated ballistic-resistant assemblywith positive buoyancy.
 85. The assembly of claim 81, further comprisinga second laminate film, the ballistic-resistant fiber strands and thebonding fibers being laminated between the first and second laminatefilms, the laminated ballistic-resistant fiber strands and the bondingfibers and the first and second laminate films forming a first laminatedballistic-resistant sheet; a second laminated ballistic-resistant sheet,comprising plurality of ballistic-resistant fiber strands interconnectedby a plurality of bonding fibers spaced apart from each other andlaminated between the first and second laminate films; and stitchingconnecting the second laminated ballistic-resistant sheet to the firstlaminated ballistic-resistant sheet.